Liberty cut gemstone

ABSTRACT

A cut gemstone comprising a girdle, a crown above the girdle and a pavilion below the girdle, the crown comprising a table and the pavilion comprising a culet and a plurality of pavilion faces between the girdle and the culet, the pavilion faces comprising a plurality of constituent faces and a plurality of star faces, the star faces and constituent faces alternating in circumferential direction of the pavilion, each of the constituent faces having a first and a second cutting edge, each star face being delimited from adjacent first and second constituent faces by respectively the first and second cutting edge of the first and second constituent faces respectively, each first cutting edge of a constituent face intersecting with a second cutting edge of a consecutive constituent face thus defining first and second star points respectively, the first and second cutting edges of consecutive constituent faces diverging towards the culet causing the first and second cutting edges of one single constituent face to intersect in a top of the constituent face, the star faces thus defining a visible star-shaped figure between them, the star-shaped figure comprising the culet. The cut gemstone according to the invention has an enhanced brilliance, contrast, fire and scintillation by adding specific facets in the pavilion.

BACKGROUND OF THE INVENTION

The value of gemstones, in particular of gemstones like diamonds, isgenerally estimated by four determining characteristics, known to theperson skilled in the art as: carat, clarity, colour and cut. A commoncut is known as the “brilliant cut”, which is a round-shaped cut. Thebrilliant cut has 58 facets: the table, the culet, 32 crown facetsbetween the table and the girdle and 24 pavilion facets between thegirdle and the culet. All the facets are arranged round an eight-foldsymmetry axis extending from the culet towards the centre of symmetry ofthe table. When looking through the table towards the culet a greatamount of incident light is internally reflected to a spectator lookingthrough the cut gemstone towards the culet, this effect is known to theperson skilled in the art as the brilliance of the stone. When lookingthrough the table towards the culet, no image of a star is reflectedtowards the spectator.

In another round-shaped cut known as the “Lone Star Cut” the pavilioncomprises a five-pointed symmetrical star, in the form of a pentagram,which represents the public symbol of The State of Texas. Thereto thepavilion of the cut comprises five star faces extending from the culettowards the girdle. Each star face is subdivided into two longitudinalfacets by a cutting edge connecting each star point with the culet. Thestar faces are surrounded by several other facets. When looking throughthe table towards the culet, incident light is reflected back to itsorigin thus reflecting the image of the star faces to the spectator. Thereflected image of the star is clearly discernable from otherreflections created by the surrounding facets. The visibility of thestar is however connected with a loss of brightness, fire andscintillation of the cut gemstone since the discernability of the staris caused by a darker reflection of the star compared to the surroundingfacets, thus decreasing the splendour and value of the cut gemstone.

Other known cut gemstones, for example some designs from the CharlesCovill Odds Collection, are similar to the cut as disclosed in thepreamble but the cut gemstone has a reduced brilliance and the image ofthe star is not clearly reflected towards the spectator looking into thecut gemstone, the reflection of the star is for example distorted by themany facets comprised in the crown of the cut gemstone, making itimpossible to distinguish a reflected star-shaped figure in the manyreflections.

SUMMARY OF THE INVENTION

The present invention relates to a mixed cut gemstone, according to thepreamble of the first claim.

The present invention seeks to add improvements to the existinggemstones and aims at providing a cut gemstone in which a figureresembling a star is reflected clearly visibly towards the spectatorwith an enhanced brilliance.

It is a further object of this invention that the star resembling figurereflected back to the spectator is surrounded by stripes in order tocreate the so-called star and stripes effect.

This is achieved according to the present invention with a cut gemstoneshowing the technical features of the characterising portion of thefirst claim.

Thereto, each constituent face comprises a third cutting edge extendingfrom the top towards the girdle, a fourth and a fifth cutting edgeextending from the first and second star point towards the third cuttingedge, the third, fourth and fifth cutting edge converging into a singlefirst intersection point, the first and the fourth cutting edgesdefining within the constituent face a first star delimiting facet alonga first side of the third cutting edge, the second and fifth cuttingedge defining with the constituent face a second star delimiting facetalong a second side of the third cutting edge opposite the first stardelimiting facet, the fourth and fifth cuffing edges definingcircumferential facets on a first side of a first striping cutting edge,the first striping cutting edges extending between adjacent first andsecond star points, a striping facet extending along a second side ofthe first striping cutting edge opposite the circumferential facet, thestriping facets comprising a second striping cutting edge extending froma first star point towards the girdle and a third striping cutting edgeextending from a second star point towards the girdle, thus formingconcatenated striping facets over the circumference of the pavilion.

The inventors have found that in providing the pavilion with stardelimiting facets a clearly visible figure is reflected by the stone,which resembles a star. The star delimiting facets help the spectator todiscern the star resembling figure from other reflections and thus addto the visibility of the reflection of the star-shaped figure. The stardelimiting facets also increase the amount of light reflected backtowards the spectator thus adding to the brilliance of the cut gemstoneaccording to the invention. Next to adding splendour to the cutgemstone, the added brilliance also increases the value of the cutgemstone according to the invention.

The inventors have further found that in adding facets to the pavilionhaving first striping cutting edges which interconnect pairs of adjacentstar points, the star-shaped figure is reflected surrounded by stripes,thus creating an effect of star and stripes for the spectator. Thefacets added this way further increase the light reflected back to thespectator and thus increase the brilliance of the cut gemstone and thusfurther add to the splendour and value of the cut gemstone.

Moreover, the inventors have found that the second and third stripingcutting edges, reflected through the cut gemstone, create additionalstripes which surround the reflected star-shaped figure. In that way animproved delimitation of the star resembling figure from the otherreflections in the cut gemstone is obtained and the overall splendourand value of the cut gemstone is improved.

The inventors have further surprisingly found that secondary reflectionsof the first, second and third striping cutting edges, of the star facesand of the star delimiting facets surprisingly occur in the cut gemstonethus even more increasing the splendour and value of the cut gemstone.The secondary reflections also delimit the reflected star-shaped figuremore clearly and allow the star-shaped figure to clearly stand out.

The inventors have moreover surprisingly found that the number andeffect of the secondary reflections of the first, second and thirdstriping cutting edges, of the star faces and of the star delimitingfacets is increased by adding the striping facets and thecircumferential facets to the pavilion thus adding to the overallsplendour and value of the cut gemstone.

The image of the star-shaped figure together with the total of thestripes surrounding the star-shaped figure account for the so calledstar and stripes effect.

In a preferred embodiment of this invention the cut gemstone ischaracterised in that the first star delimiting facet comprises at leastone first emphasizing cutting edge which extends from the first starpoint and in that second star delimiting facet comprises at least onesecond emphasizing cutting edge which extends from the second starpoint, the first and second emphasizing cutting edges converging to eachother and intersecting with the third cutting edge at a secondintersection point. Due to the presence of the emphasizing edges,visibility of the reflected star-shaped figure is further increasedwhich allows the star to stand out in the total of the reflections ofthe cut gemstone. The emphasizing cutting edges also further increasethe brightness, contrast, fire and scintillation of the cut gemstone.

In further preferred embodiments of this invention the cut gemstoneaccording to the invention is characterised in that the first stripingedges form a regular polygon, the constituent faces are congruent, thestar delimiting facets are congruent, the star faces are congruent, thestriping facets are congruent, the second and third striping cuttingedges are of equal length, the pavilion comprises an axis of symmetryhaving a symmetry number and the axis of symmetry comprises the culet,the symmetry number equals the number of star points, the crown has anaxis of symmetry corresponding to the axis of symmetry of the pavilionand finally in that the table is a regular polygon delimited by a numberof table cutting edges equal to the symmetry number, the cutting edgesof the polygon intersecting in respective corners of the polygon. Nextto improving the visibility of the reflected star-shaped figure andstripes, the high degree of symmetry of the thus cut gemstone allowsincident rays to be readily and uniformly reflected towards the table,thus adding to the brilliance of the cut gemstone. The high degree ofsymmetry for a great deal contributes to increasing the value of the cutof the cut gemstone and thus the symmetry to great extend adds to thetotal value of the cut gemstone.

The high degree of symmetry allows incident light to be reflected in aprinciple direction which corresponds to the looking direction of aspectator, thus adding to the brightness, contrast, fire andscintillation and thus to the splendour of the cut gemstone as a whole.

The reflection of the striping cutting edges, star faces and stardelimiting facets by incident rays of light is also improved due to thehigher degree of symmetry, thus adding to the visibility of thestar-shaped figure and the striping effect by reflecting the star-shapedfigure and the striping cutting edge directly to the spectator or bycausing secondary reflections.

Other details and advantages of the cut gemstone according to theinvention will become apparent from the enclosed figures and descriptionof preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a preferred embodiment of the crown of a cut gemstoneaccording to the invention.

FIG. 2 shows a preferred embodiment of the pavilion of a cut gemstoneaccording to the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The preferred embodiment of the cut gemstone (1) shown in FIGS. 1 and 2comprises a girdle (3), a crown (2) above the girdle (3) and a pavilion(4) below the girdle (3).

The pavilion (4) comprises pavilion faces (32) cut under differentangles with the girdle (3) and a culet (6). The pavilion faces (32)comprise star faces (23) and constituent faces (21, 22).

The star faces (23) and the constituent faces (21, 22) alternate incircumferential direction over the pavilion (4). Each constituent face(21, 22) comprises at least a first (11) and second (12) cutting edge.Each star face (23) is delimited from adjacent constituent faces (21,22) by respectively the first (11) and second (12) cutting edge of therespective adjacent faces (21, 22). Every first cutting edge (11) of afirst constituent face (21) intersects with a second cutting edge (12)of a second consecutive constituent face (22) in a star point (9). Everysecond cutting edge (12) of a first constituent face (21) intersectswith a first cutting edge (11) of a second consecutive constituent face(22) in a star point (10).

The first (11) and second (12) cutting edges of consecutive constituentfaces (21, 22) intersect in a star point (9, 10) and converge towardsthe culet (6) so that first (11) and second (12) cutting edges of singlefirst constituent faces intersect in a top (28), pointing towards theculet (6) of the constituent face (21).

The first (11) and second (12) cutting edges can have any length deemedappropriate by the person skilled in the art, however first (11) andsecond (12) cutting edges of a single constituent face (21, 22)preferably have the same length.

The alternating arrangement of the constituent faces (21, 22) and thestar faces (23) and the aforementioned positioning of the constituentfaces (21, 22) cause that the constituent faces (21, 22) define astar-shaped figure (33) between them. The star-shaped figure (33)comprises the star faces (23) and the culet (6).

The star faces (23) can have any shape deemed appropriate to the personskilled in the art but preferably are four-sided polygons, morepreferably kites. Preferably, every kite is delimited by a first (11)and second (12) cutting edge of consecutive constituent faces (21, 22)and two cutting edges each one extending from the culet (6) towards thetop (28) of the consecutive constituent face (21, 22). The dimensions ofthe individual star faces (23) are not critical to the invention butpreferably all star faces are congruent.

The constituent faces (21, 22) comprise a third cutting edge (13) whichextends from the top (28) towards the girdle (3) and fourth (14) andfifth (15) cutting edges which extend from the first (9) and second (10)star point respectively and extending towards the third cutting edge(13). The third (13), the fourth (14) and the fifth (15) cutting edgesconverge into a single first intersection point (29).

The fourth cutting edge (14) can have any length deemed appropriate bythe person skilled in the art but preferably is smaller than the lengthof the first cutting edge (11). The fifth cutting edge (15) can have anylength deemed appropriate by the person skilled in the art butpreferably is smaller than the length of the second cutting edge (12).More preferably the fourth (14) and the fifth (15) cutting edges have anequal length.

The length of the first (11), second (12), third (13), fourth (14) andfifth (15) cutting edges determine the visibility and shape of thestar-shaped figure (33) reflected by the cut gemstone (1), is furtheralso determining for the brightness, contrast, fire and scintillation ofthe cut gemstone (1) as a whole and is dependent on the material usedfor the cut gemstone (1) and the size of the original uncut gemstone butcan be determined by the person skilled in the art.

The first (11), the third (13) and the fourth (14) cutting edges offirst constituent faces (21) define a first star delimiting facet (24).The second (12), the third (13) and the fifth (15) cutting edges offirst constituent faces (21) define a second star delimiting facet (25).The first (24) and second (25) star delimiting facets can have any shapedeemed appropriate to the person skilled in the art but preferably aretriangular, more preferably they are all congruent.

The first constituent faces (21) further comprise first striping cuttingedges (18) along the circumference of the pavilion (4) extending betweenadjacent first and second star points (9, 10). Preferably the firststriping cutting edges (18) connect adjacent star points (9, 10). Fourth(14) and fifth (15) cutting edges and first striping cutting edges (18)define circumferential facets (26). The shape of the circumferentialfacets (26) is not critical to the invention but preferably istriangular.

A second striping cutting edge (19) extends from the first star points(9) towards the girdle (3) and a third striping cutting edge (20)extends from the second star points (10) towards the girdle (3) and thesecond striping cutting edge (19). The second (19) and third (20)striping cutting edges intersect and define together with the firststriping cuffing edges (18) striping facets (27). The striping facets(27) can have any shape deemed appropriate to the person skilled in theart but preferably is triangular.

The length of the second (19) and third (20) striping cutting edges isnot critical to the invention but can be determined by the personskilled in the art. Preferably the second (19) and third (20) stripingcutting edges intersect near the edge of the girdle (3) of the cutgemstone (1) but this is not critical to the invention. The length ofthe second (19) and third (20) striping cutting edge is not critical tothe invention but preferably the length of the second (19) and third(20) striping cutting edge is equal in each striping facet (27). Morepreferably, the first striping cutting edges (18) form a polygon and thesecond (19) and third (20) striping cutting edges intersect on the edgeof the girdle (3). Even more preferably, the different striping facets(27) are congruent.

The star delimiting facets (24, 25) preferably comprise additionalemphasizing cutting edges (16, 36, 17, 37), spread arbitrarily over thestar delimiting facets (24, 25). The emphasizing cutting edges (16, 36,17, 37) add to the splendour of the cut gemstone (1) by increasingvisibility of the reflection of the star-shaped figure (33) so that thestar-shaped figure (33) stands out in the total of the reflections ofthe cut gemstone (1) and add to the brightness, contrast, brilliance,fire and scintillation of the cut gemstone (1).

The position of the emphasizing cutting edges (16, 36, 17, 37) can bedetermined by the person skilled in the art, but preferably theemphasizing cutting edges (16, 36, 17, 37) extend from first (9) and/orsecond star points (10) from a first constituent face (21) and intersectwith the third cutting edge (13) of the first constituent face (21). Theemphasizing cutting edges (16, 36, 17, 37) can have any shape deemedappropriate for the person skilled in the art but preferably arestraight. Each star delimiting facet (24, 25) can have any number ofemphasizing cutting edges (16, 36, 17, 37) but preferably the first stardelimiting facet (24) comprises first emphasizing cutting edges (16, 36)extending from the first star point (9) positioned between thecircumferential facet (26) and a star face (23) adjacent to the firstcutting edge (11) and the second star delimiting facet (25) comprisessecond emphasizing cutting edges (17, 37) extending from the second starpoint (10) positioned between the circumferential facet (26) and a starface adjacent to the second cutting edge (12) extending from the secondstar point 10. More preferably the first (24) and second (25) stardelimiting facets comprise two first emphasizing cutting edges (16, 36)and two second emphasizing cutting edges (17, 37) respectively. Firstemphasizing cutting edges (16) and second emphasizing cutting edges (17)preferably converge with the third cutting edge (13) of the constituentface (21) in a single second intersection point (30).

The first and second emphasizing cutting edges (16, 17, 36, 37) can haveany length deemed appropriate by the person skilled in the art butpreferably first emphasizing cutting edges (16, 36) and secondemphasizing cutting edges (17, 37) have the same length. More preferablythe constituent faces (21) are congruent. Thus a symmetrical star-shapedfigure (33) is created since preferably the star faces (23) and the stardelimiting facets (24, 25) are congruent and the first (16, 36) andrespective second emphasizing cutting edges (17, 37) are equal.

Additional facets (38) can be cut along the striping facets (27),between the girdle (3) and the striping facets (27). In a preferredembodiment of the invention an additional cutting edge extends fromevery star point (9, 10) towards the girdle (3) thus creating additionalfacets delimited by the aforementioned cutting edge extending from thestar points (9, 10), a cutting edge of the girdle (3) and the second orthird striping cutting edge (19, 20). These additionally cut facetsalong the striping facets (27) can have any shape deemed appropriate bythe person skilled in the art but preferably are triangular and morepreferably are congruent.

A primary image of the star faces (23) surrounded by adjacent stardelimiting facets (24, 25) is reflected directly towards the spectatorin the form of a star, wherein the centre of the star coincides with theculet (6). Moreover, secondary images of the star faces (23) surroundedby adjacent star delimiting facets (24, 25) are reflected to thespectator. In case the star-shaped figure (33) comprises an unevennumber of star points (9, 10) the secondary images of the star faces(23) surrounded by adjacent star delimiting facets (24, 25) arereflected to the spectator at a position between consecutive legs of thestar. Thus created secondary reflections extend from the centre of thetable (5) towards the girdle (3) in the spaces left by the primaryimage. The secondary images are created by secondary reflections of theprimary image of the star faces (23) and the star delimiting facets (24,25) reflected by circumferential (26) and striping (27) facets on anopposed side of the star faces (23) and star delimiting (24, 25) facetsof the cut gemstone (1).

Additionally, primary images of cutting edges (18, 19, 20) surroundingthe star-shaped figure (33) are reflected directly towards a spectator,next to secondary images of the surrounding cutting edges (18, 19, 20)reflected by facets on an opposite side of the cut gemstone (1). Thesecondary images of the surrounding cutting edges take the form ofcircumferential stripes which surround the star-shaped figure (33).

The primary and secondary images of the star faces (23), the stardelimiting facets (24, 25) and the cutting edges (18, 19, 20) add to theoverall splendour of the cut gemstone (1) and thus substantiallycontribute to its total value.

The relative shape, angle with the girdle (3) and size of the star faces(23), the star delimiting facets (24, 25), the circumferential facets(26) and the striping facets (27) are determining for the brightness,contrast, fire and scintillation of the cut gemstone (1) as a whole andare dependent on the material used for the cut gemstone (1) and the sizeof the original uncut gemstone. Furthermore, the shape, size and anglewith the girdle (3) of the circumferential facets (26) and the stripingfacets (27) are determining for reflecting light towards the spectatorand thus for the extend to which the secondary image of the star-shapedfigure (33) and the secondary image of the surrounding cutting edges(18, 19, 20) is reflected towards a spectator. These determining factorscan be determined by the person skilled in the art.

The culet (6) preferably comprises a first axis of symmetry having afirst symmetry number. In a more preferred embodiment the first symmetrynumber equals the number of star points (9, 10). The first symmetrynumber can be three, four, five, six, seven, eight or more butpreferably is uneven due to the possibility of secondary images of thestar faces (23) surrounded by adjacent star delimiting facets (24, 25)reflected to the spectator at a left open position between consecutivelegs of the star. The number of additional facets (38) along thestriping facets (27) preferably is twice the first symmetry number. Incase the symmetry number is five the reflected images of the star-shapedfigure (33) symbolize the characterising element of the United StatesFlag, the Stars and Stripes.

Preferably the pavilion (4) comprises a first axis of symmetry of whichthe first symmetry number is five, the number of star points equals thefirst symmetry number and the number of additional facets adjacent tothe striping facets (27) is ten. When looking directly to the culet, thefirst striping cutting edges (18) form a first pavilion pentagondelimiting the constituent faces (21, 22). The second (19) and third(20) striping cutting edges form a second pavilion pentagoncircumscribing the first pentagon. Finally a pavilion decagoncircumscribing the second pentagon is formed by cutting edges of thegirdle (3).

Since the different striping facets (27) preferably are congruent, thedifferent first and second striping cutting edges (19, 20) have the samelength. The corner points of the first pavilion pentagon therefore arelocated in the middle of each of the sides of the second pavilionpentagon. The pavilion decagon circumscribes the second pavilionpentagon in such a way that every other corner point of the paviliondecagon coincides with the corner points of the second pavilionpentagon.

The crown (2) comprises a table (5) and a number of other crown facets(31). The crown facets (31) can comprise any number of additional facetsdeemed appropriate by the person skilled in the art.

The table (5) comprises a number of table cutting edges (34)intersecting in table corners (35). The table (5) can be of any shapedeemed appropriate by the person skilled in the art but preferably islarge enough so that a spectator can clearly see the reflected primaryimages of the star faces (23), the star delimiting facets (24, 25) andpreferably surrounding cutting edges (18, 19, 20). More preferably thetable (5) also allows that secondary reflections of the star faces (23)and the star delimiting facets (24, 25) and/or secondary reflections ofthe surrounding cutting edges (18, 19, 20) are clearly visible for aspectator.

The shape, angle with the girdle (3) and number of the additional crownfacets (31) surrounding the table (5) can be determined by the personskilled in the art and are not critical to the invention. The shape,angle with the girdle (3) and number of the additional crown facets (31)are determining for the brightness, contrast, fire and scintillation ofthe cut gemstone (1) as a whole and are dependent on the material usedfor the cut gemstone (1) and the size of the original uncut gemstone.

Preferably first additional crown facets (45) extend from the cuttingedges (34) of the table (5) and extend towards the girdle (3).Preferably these first additional crown facets (45) are delimited by acutting edge (34) of the table (5) and two first additional crowncutting edges (39, 40). The first additional crown facets (45) can be ofany shape deemed appropriate by the person skilled in the art butpreferably are triangular.

Preferably a second additional crown facet (46) extends from every firstadditional cutting edge (39, 40) of the first additional crown facets(45) and extends towards the girdle (3). Preferably these secondadditional crown facets (46) are delimited by a first additional cuttingedge (39, 40) of a first additional crown facet (45) and two secondadditional cutting edges (41, 42). The second additional crown facets(46) can be of any shape deemed appropriate by the person skilled in theart but preferably are triangular.

Preferably third additional crown facets (47) extend from the secondadditional cutting edges (41, 42) of the second additional crown facets(46) and extend towards the girdle (3). Preferably these thirdadditional crown facets (47) are delimited by a second additionalcutting edge (41, 42) of a second additional crown facet (46), a cuttingedge of the girdle (3) and a third additional cutting edge (43). Thethird additional crown facets (47) can be of any shape deemedappropriate by the person skilled in the art but preferably aretriangular.

The relative shape, angle with the girdle (3) and size of the first,second and third additional crown facets (45, 46, 47) can be determinedby the person skilled in the art and is not critical to the invention.

Preferably, second additional crown facets (46) comprise a subdividingcutting edge 44 which extends from the corner points of the table (5)towards the intersection points of the second additional cutting edges(41, 42).

Preferably, additional first crown facets (45) are congruent, secondadditional crown facets (46) are congruent and/or third additional crownfacets (47) are congruent. Even more preferably the table (5) is aregular polygon. Preferably the table (5) comprises a second axis ofsymmetry (7). The second axis of symmetry (7) goes through anintersection point (8) with the table, has a second symmetry number andpreferably also is an axis of symmetry of the whole crown (2). Morepreferably, the number of table cutting edges (34) equals the secondsymmetry number.

Preferably, the second axis of symmetry (7) is collinear with the firstaxis of symmetry. More preferably the first symmetry number equals thesecond symmetry number. The second symmetry number can be three, four,five, seven, eight or more but preferably is five.

More preferably, when looking down straight onto the table (5) the firstadditional cutting edges (39, 40) of the first additional facets (45)form a first crown polygon circumscribing the table (5), the first crownpolygon comprising first polygon corner points and first polygon sides.More preferably, the second additional facets (46) form a second crownpolygon circumscribing the first crown polygon, the second crown polygoncomprising second polygon corner points. Preferably, the second crownpolygon corner points are positioned on a cutting edge of the girdle(3). The cutting edges of the girdle (3) preferably form a third crownpolygon circumscribing the second crown polygon. Preferably, the table(5) and the first and second crown polygons are regular pentagons andthe third crown polygon is a regular decagon.

More preferably, the corner points (35) of the table (5) are located inthe middle of the sides of the first crown polygon and the third crownpolygon circumscribes the second crown polygon in such a way that everyother corner point of the third crown polygon coincides with a cornerpoint of the second crown polygon.

The star points (9, 10) of the star-shaped figure (33) can be positioneddeemed appropriate by the person skilled in the art but preferably, fora spectator looking down into the table, on an imaginary line connectingthe intersection point (8) of the axis of symmetry (7) with the cornerpoints of the first crown polygon, which preferably is a pentagon. Thestar-shaped figure is however more preferably positioned with its starpoints (9, 10) positioned on an imaginary line connecting theintersection point (8) of the axis of symmetry (7) with the cornerpoints (35) of the table (5).

The shape and size of the star-shaped figure (33) in relation to theshape and size of the table (5) can be determined by the person skilledin the art but preferably the length of the side of the first crownpolygon equals the length of the sides of the first pavilion pentagon

The different relative shapes, sizes and angles in relation to thegirdle (3) of the different cutting edges, faces and facets can bedetermined by the person skilled in the art in function of the desiredbrightness, contrast, fire and scintillation of the cut gemstone and arealso dependent on the material, size and characteristics of the cutgemstone.

The striping facets (27) are usually positioned under an angle of 50 to55° with respect to the table (5), the second additional crown facets(46) are usually positioned under an angle of between 30° and 36° withrespect to the table (5). If the angle becomes larger than 55°, theheight of the stone will increase which goes at the expense of thereflection of the star through the table (5). The star faces (23) areusually positioned under an angle of between 37.5° and 41.5° withrespect to the table (5). The striping facets (27) have a height whichis (20) to 40% of the height of the pavilion (4). The height of thestar-shaped figure is preferably 80-60% of the height of the pavilion(4). If the angle becomes less than 30° the dimensions of the table (5)would decrease to such an extent that the star would no longer bevisible through the table (5).

1. A cut gemstone comprising a girdle, a crown above the girdle and apavilion below the girdle, the crown comprising a table and the pavilioncomprising a culet and a plurality of pavilion faces between the girdleand the culet, the pavilion faces comprising a plurality of constituentfaces and a plurality of star faces, the star faces and constituentfaces alternating in circumferential direction of the pavilion, each ofthe constituent faces having a first and a second cutting edge, eachstar face being delimited from adjacent first and second constituentfaces by respectively the first and second cutting edge of the first andsecond constituent faces respectively, each first cutting edge of aconstituent face intersecting with a second cutting edge of aconsecutive constituent face thus defining first and second star pointsrespectively, the first and second cutting edges of consecutiveconstituent faces diverging towards the culet causing the first andsecond cutting edges of one single constituent face to intersect in atop of the constituent face, the star faces thus defining a visiblestar-shaped figure between them, the star-shaped figure comprising theculet, characterised in that each constituent face comprises a thirdcutting edge extending from the top towards the girdle, a fourth and afifth cutting edge extending from the first and second star pointtowards the third cuffing edge, the third, fourth and fifth cutting edgeconverging into a single first intersection point, the first and thefourth cutting edges defining within the constituent face a first stardelimiting facet along a first side of the third cutting edge, thesecond and fifth cutting edge defining with the constituent face asecond star delimiting facet along a second side of the third cuttingedge opposite the first star delimiting facet, the fourth and fifthcutting edges defining circumferential facets on a first side of a firststriping cutting edge, the first striping cutting edges extendingbetween adjacent first and second star points, a striping facetextending along a second side of the first striping cutting edgeopposite the circumferential facet, the striping facets comprising asecond striping cutting edge extending from a first star point towardsthe girdle and a third striping cutting edge extending from a secondstar point towards the girdle, thus forming concatenated striping facetsover the circumference of the pavilion.
 2. The cut gemstone according toclaim 1, characterised in that the first star delimiting facet comprisesat least one first emphasizing cutting edge which extends from the firststar point and in that second star delimiting facet comprises at leastone second emphasizing cutting edge which extends from the second starpoint 10, the first and second emphasizing cutting edges converging toeach other and intersecting with the third cutting edge at a secondintersection point.
 3. The cut gemstone according to claim 2,characterised in that each first and second star delimiting facetcomprises two emphasizing cutting edges.
 4. The cut gemstone accordingto claim 1, characterised in that the first striping edges form aregular polygon.
 5. The cut gemstone according to claim 1, characterisedin that the constituent faces are congruent.
 6. The cut gemstoneaccording to claim 1, characterised in that the star delimiting facetsare congruent.
 7. The cut gemstone according to claim 1, characterisedin that the star faces are congruent.
 8. The cut gemstone according toclaim 1, characterised in that the striping facets are congruent.
 9. Thecut gemstone according to claim 1, characterised in that the second andthird striping cutting edges are of substantially equal length.
 10. Thecut gemstone according to claim 1, characterised in that the pavilioncomprises a first axis of symmetry which extends from the culet to thetable, having a first symmetry number, and in that the axis of symmetrycomprises the culet.
 11. The cut gemstone according to claim 10,characterised in that the first symmetry number of the first axis ofsymmetry equals the number of star points.
 12. The cut gemstoneaccording to claim 10, characterised in that the crown comprises asecond axis of symmetry which corresponds to the first axis of symmetryof the pavilion.
 13. The cut gemstone according to claim 10,characterised in that the table is a regular polygon delimited by anumber of table cutting edges equal to the first symmetry number, thecutting edges of the polygon intersecting in respective corners of thepolygon.
 14. The cut gemstone according to claim 13, characterised inthat, when looking through the crown towards the culet, star points lieon a line connecting the intersection of the first axis of symmetry withthe table with the corners of the polygon forming the table.
 15. The cutgemstone according to claim 10, characterised in that the first symmetrynumber is three, four, five, six, seven eight or more.